When the first models came out in 2011, it had recoil spring, ejector problems and even some extraction issues. It took about a year, but by January of 2012, I think they corrected the main issues.
I bought mine in January of 2012 with the corrected parts for the above problems. I have fired all types of loads without a single problem. The only slight noticible thing is that the brass ejects a little more erratically in direction with 115 grain loads, than with heavier loads, like 124g or 147g bullets that ejected at the 45 degree angle almost all the time.